package com.youximao.sdk.lib.common.common.util;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

/**
 * MD5加密工具
 *
 * @author xiaoli<xiaoli@zjyushi.com>
 * @version 0.1
 * @time Mar 27, 2015
 * @since 0.1
 */
public class MD5Util {

    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};

    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++)
            resultSb.append(byteToHexString(b[i]));

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0)
            n += 256;
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = origin;
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname))
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes()));
            else
                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes(charsetname)));
        } catch (Exception exception) {
        }
        return resultString;
    }

    /**
     * MD5加密方法
     *
     * @param input
     * @return
     * @throws NoSuchAlgorithmException
     * @author xiaoli<xiaoli@zjyushi.com>
     * @time Mar 27, 2015
     * @version 0.1
     * @since 0.1
     */
    public static String MD5(String input) {
        if (input == null || input.length() == 0)
            return "";

        String out = "";
        byte[] output;
        MessageDigest m;
        try {
            m = MessageDigest.getInstance("MD5");

            output = m.digest(input.getBytes());
            int len = output.length;

            for (int i = 0; i < len; i++) {

                String t = Integer.toHexString(output[i] & 0x00FF);

                out += (t.length() == 1) ? ("0" + t) : t;

            }
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return out;
    }
}
